Enhancing rice productivity and mitigating greenhouse gas emissions through manure maturity and water management in paddy soils

Abstract

This study investigates the influence of manure maturity and water management practices on greenhouse gas (GHG) emissions and rice yield in paddy soils. Field experiments were conducted with different manure types (raw and mature) under two water management conditions: flooded and non-flooded. The emissions of carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) were measured throughout the growing season, alongside rice yield, global warming potential (GWP), and greenhouse gas intensity (GHGI). The results revealed that mature manure (B2) under flooded conditions (G2) significantly reduced CO₂ and CH₄ emissions while enhancing rice yield (5.87 tons/ha) compared to raw manure treatments. The B2G2 treatment demonstrated the lowest GWP (153.49 kg CO₂e/ha) and GHGI (26.16 kg CO₂e/kg grain yield), indicating optimal environmental efficiency. In contrast, the B1G1 treatment (raw manure under non-flooded conditions) resulted in the highest GHG emissions and the lowest rice yield (3.57 tons/ha). This study highlights the potential of integrating mature organic amendments with controlled water management to reduce the environmental impact of rice cultivation while maintaining high productivity, offering a sustainable approach to rice farming in the face of climate change challenges.